Electrode system



Oct. 25, 1938. PUTZER 2,134,577

ELECTRODE SYSTEM Filed July 22, 1937 WITNESSES: INVENTOR A/fred PufzerATTORNEY Patented Oct. 25, 1938 ELECTRODE SYSTEM Alfred Piitzer,Berlin-Spandau, Germany, asslgnor to Siemens & HalskeAktiengesellschatt, Siemensstadt, near Berlin, Germany, a corporation ofGermany Application July 22,

1937, Serial No. 154,952

In Germany July 23, 1936 5 Claims.

The invention relates to discharge devices and especially tosuchidevices utilizing a hot cathode.

An object of the invention is to conserve heat energy applied to a hotcathode of a discharge device.

Another object ofthe invention is to prevent back-iires in hot cathodedevices.

Other objects and advantages of the invention will be apparent from thefollowing description and drawing, ginwhich:

Figure 1 is a view partly in cross section of a preferred embodiment ofthe invention, and

Figs. 2 and 3 arem'odifications of the invention disclosed in Fig. 1. I

Specifically stated, the invention concerns the utilization of curvedreflectors or shields or caps about the ends; of a hot cathode for thepurpose of conserving the heat and to provide a more uniform temperaturethroughout the length of the cathode. At the same time, the shields arelocated intermediate between the two main electrodes and back-fire fromthe anode or an and preferably is in-the form of turns extending fromone end it to the other end l5 where both are connected to the standardsII and I2. About the ends I 4 and 15 are placed curved shields or disksl6 and I1, preferably in conical shape. It is preferred to utilize twoanodes l8 and i 9 although the invention is applicable to a single pairof main electrodes. These anodes l8 and H! are preferably annular ringswith central openings 20 and H and these anodes are supported on thestandards and leads 22 and 23. It is preferred to have the conicalshields l6 and ll located with their apexes 24 and 25 extending withinthe openings 20 and 2| of the anodes.

Inasmuch as the device is particularly adapted to gas or vapor filleddevices, such as the noble gases or mercury vapor, it is preferred tolocate the reflectors or shields l6 and I1 within the mean free pathdistance oftheir respective anodes l8 and I 9, in order that there maybe no, discharge therebetween. The conical shields or reflectors l6, I!are preferably supported directly upon the cathode standards II and I2and may have a poor heat conducting connection thereto (Cl. 2502'l.5)

at 26 and 21. Inst/ead'the reflector shield may be made of poor heatconducting material.

any event, the shields are preferably very smooth on their surface andare preferably highly pol-.

ished towards the cathode at least in order to reflect heat back to theturns.

It will be noted that the cathode will be prevented from radiating heatto the side walls of the tube, except for the small space between thetwo conical reflectors that is left for the passage of electrons to theanodes.

Inasmuch as the shields are intermediate the anode and cathode, a'direct back-fire from one to the other is likewise prevented.

In Fig. 2, there is disclosed a modification in l6 and H. and be of asolid instead of a This electrode may take other forms mesh constructionsupported on a lead-in standard 29.

In Fig. 3, there is disclosed a still further modification in which twocontrol grids 30 and 3| are disclosed as hollow members preferably in amesh form with central openings 32 and 33 placing them about the conicalshields l6 and H.

Fig. 3, the mesh of the grids lies in the electron path from the cathodei3 around the edges of the curved reflectors to the anodes.

It will be noted that in the various figures, the standards and lead-inscan be located axially aligned.

all in one plane on the press it) and that the electrodes are Thereflectors prevent the cooling that would otherwise take place at theends of the cathode due to radiation. Because the anodes are ringshapedand the caps penetrate the rings, space is saved and the arrangement iseasily mountable.

By the ring-shaped construction of the anodes, their radiation surfaceis increased, their temperature is maintained lower and the danger ofback-fire is decreased. No particleoi cathode coating can be sputtereddirectly to the anode because oi. the shield.

The hot cathode is preferably a" helix with a coating of good electronemissive material.

The

This is advantageous during the manufacture,

and for gas filled discharge vessels it is desirable for the sake ofattaining a the space charge.

better removal of While there has been shown preferred embodiments ofthe invention, it is apparent that many changes may be made in theshape, arrangement and number of the elements. Accordingly, it isdesired that only such limitations be imposed on the following claims asis necessitated by the prior art.

I claim as my invention:

1. A discharge device comprising an annular anode, an incandesciblecathode and a curved reflector around one end of said cathode andextending within said annular anode.

2. A discharge device comprising an annular anode, a cathode and aconical member having its apex extending within said annular anode andits edges around a portion of said cathode.

3. A discharge device comprising an anode having an openingtherethrough, a conical member having its apex extending within theopening in said anode, a cathode, said conical member having its edgesaround a portion 01 said cathode.

4.. A discharge device comprising a cathode, anodes having openingstherein and positioned adjacent the respective ends of said cathode andconical reflectors intermediate said anodes and said cathode and havingtheir apexes within said anode openings.

5. A discharge device comprising an annular anode, an incandesciblecathode, a curved reflector intermediate said cathode and said anode andan annular control electrode located in the discharge space between saidanode and cathode.

ALFRED PfiTZER.

